1. Field of the Invention
This invention relates to a method of displaying digital documents in portable document format (PDF), and in particular, it relates to a method for dynamically displaying multi-layered PDF documents.
2. Description of Related Art
PDF is a popular format for generating, distributing and displaying digital documents. Many PDF documents are generated with one or more embedded optional content group (OCG) layers. For example, a document intended to be read by people reading different languages may have multiple layers where each layer contained text and images in one of many languages. With this multi-layered document, a user may select a particular one of the many languages to display the document in that particular language, without having to download a new version of the document for that language.
It is desirous to provide a method for dynamically displaying PDF documents embedded with multiple layers so that users may choose to display only the contents satisfying certain predetermined criteria.